# +_+ coding:utf-8

class Const(object):
    def __init__(self):
        pass

    class ConstError(TypeError):
        pass

    def __setattr__(self, key, value):
        if self.__dict__.has_key(key):
                raise self.ConstError, "It's a Const"

        self.__dict__[key] = value

    def __delattr__(self, item):
        if self.__dict__.has_key(item):
            raise  self.ConstError, "Can't Delete a Const"

        raise AttributeError, "Const Don't has the attr"


import sys
sys.modules[__name__] = Const()